From 38500aa8d4824106616496c9449e854e3a090830 Mon Sep 17 00:00:00 2001
From: Pim van Pelt <pim@ipng.nl>
Date: Mon, 2 Apr 2018 22:05:53 +0200
Subject: [PATCH] Add public header documentation.

---
 include/mgos_sht31.h  | 32 +++++++++++++++++++++++++-------
 include/mgos_si7021.h | 26 ++++++++++++++++++++++----
 2 files changed, 47 insertions(+), 11 deletions(-)

diff --git a/include/mgos_sht31.h b/include/mgos_sht31.h
index 14263ea..fe73cf5 100644
--- a/include/mgos_sht31.h
+++ b/include/mgos_sht31.h
@@ -11,33 +11,51 @@ extern "C" {
 
 struct mgos_sht31;
 
-/*
- *
+/* 
+ * Initialize a SHT31 on the I2C bus `i2c` at address specified in `i2caddr`
+ * parameter (default SHT31 is on address 0x44). The sensor will be polled for
+ * validity, upon success a new `struct mgos_sht31` is allocated and
+ * returned. If the device could not be found, NULL is returned.
  */
 struct mgos_sht31 *mgos_sht31_create(struct mgos_i2c *i2c, uint8_t i2caddr);
 
-/*
- *
+/* 
+ * Destroy the data structure associated with a SHT31 device. The reference
+ * to the pointer of the `struct mgos_sht31` has to be provided, and upon
+ * successful destruction, its associated memory will be freed and the pointer
+ * set to NULL.
  */
 void mgos_sht31_destroy(struct mgos_sht31 **sensor);
 
-/*
- *
+/* 
+ * The sensor will be polled for its temperature and humidity data. If the poll
+ * has occured in the last `MGOS_SHT31_READ_DELAY` seconds, the cached data is
+ * used (so as not to repeatedly poll the bus upon subsequent calls).
  */
 bool mgos_sht31_read(struct mgos_sht31 *sensor);
 
 /*
+ * The sensor will be polled for its temperature and humidity data. If the poll
+ * has occured in the last `MGOS_SHT31_READ_DELAY` seconds, the cached data is
+ * used (so as not to repeatedly poll the bus upon subsequent calls).
  *
+ * The return value is the temperature of the sensor in Celsius, or NAN if no
+ * data was found.
  */
 float mgos_sht31_getTemperature(struct mgos_sht31 *sensor);
 
 /*
+ * The sensor will be polled for its temperature and humidity data. If the poll
+ * has occured in the last `MGOS_SHT31_READ_DELAY` seconds, the cached data is
+ * used (so as not to repeatedly poll the bus upon subsequent calls).
  *
+ * The return value is the humidity of the sensor in percent relative humidity,
+ * or NAN if no data was found.
  */
 float mgos_sht31_getHumidity(struct mgos_sht31 *sensor);
 
 /*
- *
+ * Initialization function for MGOS -- currently a noop.
  */
 bool mgos_sht31_i2c_init(void);
 
diff --git a/include/mgos_si7021.h b/include/mgos_si7021.h
index 425b57e..ea8ec39 100644
--- a/include/mgos_si7021.h
+++ b/include/mgos_si7021.h
@@ -12,32 +12,50 @@ extern "C" {
 struct mgos_si7021;
 
 /*
- *
+ * Initialize a Si7021 on the I2C bus `i2c` at address specified in `i2caddr`
+ * parameter (default Si7021 is on address 0x40). The sensor will be polled for
+ * validity, upon success a new `struct mgos_si7021` is allocated and
+ * returned. If the device could not be found, NULL is returned.
  */
 struct mgos_si7021 *mgos_si7021_create(struct mgos_i2c *i2c, uint8_t i2caddr);
 
 /*
- *
+ * Destroy the data structure associated with a Si7021 device. The reference
+ * to the pointer of the `struct mgos_si7021` has to be provided, and upon
+ * successful destruction, its associated memory will be freed and the pointer
+ * set to NULL.
  */
 void mgos_si7021_destroy(struct mgos_si7021 **sensor);
 
 /*
- *
+ * The sensor will be polled for its temperature and humidity data. If the poll
+ * has occured in the last `MGOS_SI7021_READ_DELAY` seconds, the cached data is
+ * used (so as not to repeatedly poll the bus upon subsequent calls).
  */
 bool mgos_si7021_read(struct mgos_si7021 *sensor);
 
 /*
+ * The sensor will be polled for its temperature and humidity data. If the poll
+ * has occured in the last `MGOS_SI7021_READ_DELAY` seconds, the cached data is
+ * used (so as not to repeatedly poll the bus upon subsequent calls).
  *
+ * The return value is the temperature of the sensor in Celsius, or NAN if no
+ * data was found.
  */
 float mgos_si7021_getTemperature(struct mgos_si7021 *sensor);
 
 /*
+ * The sensor will be polled for its temperature and humidity data. If the poll
+ * has occured in the last `MGOS_SI7021_READ_DELAY` seconds, the cached data is
+ * used (so as not to repeatedly poll the bus upon subsequent calls).
  *
+ * The return value is the humidity of the sensor in percent relative humidity,
+ * or NAN if no data was found.
  */
 float mgos_si7021_getHumidity(struct mgos_si7021 *sensor);
 
 /*
- *
+ * Initialization function for MGOS -- currently a noop.
  */
 bool mgos_si7021_i2c_init(void);